Mercedes 722.6 Transmission service and valve body check
The transmission I bought about 4 years ago i think. With 170D km on the running gear. So it is good to know if this number makes sense when i open the transmission for a check and little clean up. Also there are some parts that need to be changed out. Like filters and the PLIL parking lock connection.
This transmission has OEM code 722.624 These are normally in E55 AMG NA cars. So this is a transmission from around 1998. Also this transmission has still the torque converter with the drain plug in it. i think this changed around 2000.
I have drained the oil from the torque converter and from the transmission because these where still full level all the time since i had it. The oil does not look that bad. The color is pretty light for this to be the first oil. When removing the oil pan the oil filter is showing 1997 production date. So this the first filter or it can be and long on the shelf item.
The oil pan is not having a magnet. If i remember correct the early gearboxes did not have this. But im going to order this and install it.
PLIL is a part that you should always change if you open the transmission because there is a rubber piece that can break over time. and will give a very big leak. In my case i also remove the parking lock mechanism. Because this part needs to be connected with a cable in the oem cars to the steeringlock and the ignition key. In my w124 this will not work. So i will only have the parking lock from the shifter
Removing the valve body. The conductor plate is removed incl alle the solenoids. The plate looks pretty good. But i have a new one just to be sure. I will keep the old one as a spare. The valve body can be split but make sure you have the big side on the bottom. Because in this part are all the steel and plastic balls that will otherwise drop out.
After removing the the balls, filter, checkvalve and oil out of the valve body parts. I left them overnight to drain out fully. Next day i check all the springs and pistons in the valve body (see pictures below). Everything looks just like it should be.
i also drilled the 3 to 4 flare bigger to 4 mm just like on the ofgear website. This include a little software change will solve the problem
and will make the shift also under full load better then without this modification.
Im going to run a standalone OFGEAR.DK controll unit for the transmission have look on his website
This the valvebody can be assembled again with new filters. Before the conductor plate and solenoids can be mounted again, I checked the solenoids with 12v if the where werking. All are okey. The valve body can be put back in the transmission case and the new filter can be mounted. When i have the magnet for the sump i will mount the pan with a new gasket.
If there are any questions just ask
for extra info or a manual from a 722.6 visit the link below
ATSG gearbox manual
Febi biltstein Service kit : 100254
The Torque values. bolts in oil pan, valve body mounting to transmission, vale body splitting bolts M6 bolts . to 8NM
Torque value for Valve body side covers M4 bolts to 4NM
Torque value for connector bolt to 2,5NM